Conclusion
International relations between states offer one of those rare cases where lack of clear sovereignty gives rise to a prominent role for customary international law. As a rule of thumb, the limitations of international treaties that bind only states that are parties thereto and their paucity with regard to the Internet, could mean that international custom potentially becomes a truly global source of law in cyberspace between states.This is especially so given that some states have adopted practices that might conceivably be characterized as customary international law in statu nascendi. However, the doctrine of international public law has not yet endorsed this possibility. Reading textbooks on international public law does not create an impression that this area of law has attracted any degree of interest in rules pertaining to cyberspace. Yet in the past, international law has embraced technological revolutions that have led to the development of the customary law of the sea, air and cosmos. This stagnation cries out for change. The Internet showed its darker side a long time ago and has led to tensions between the major economic powers in the world. These have accused each other of cyberattacks, espionage as well as the theft of intellectual property and trade secrets. Such disputes are not fundamentally different from traditional ICJ cases concerning violations of established principles of (customary) international law. Much needs to be done, therefore, in order to prepare the doctrine of international law as a mechanism for adjudicating such disputes. In particular, this is so with regard to improving research methods and opening legal education to these new aspects of international relations.